Among the dead is the shooter, according to Cincinnati.com — The Enquirer’s website. The shooting began about 9 a.m. and was over by 9:15 a.m., the newspaper reported.

Three men and one woman were transported to the University of Cincinnati Medical Center, hospital officials told the Enquirer. Two have died at the hospital, one is in critical condition and one is in serious condition. Each suffered gunshot wounds, officials told the newspaper.

With four dead, this is the deadliest mass shooting in the Cincinnati region since 2013.

Cincinnati police reported they received the call of a shooter in the loading dock and lobby of the Fifth Third Bank at 9:10 a.m. Three of the four police officers who responded to the scene actively engaged the shooter.

The Associated Press reports that it is unclear if the gunman shot himself or was shot by officers.

Cincinnati Mayor John Cranley said the gunman was "actively shooting innocent victims" and that the building located in Fountain Square is a popular spot for ice scream, lunch and pastries.

A witness "heard about eight gunshots" and got to the ground before police arrived to the scene, according to a CNN affiliate.